Freaks of Nature

What Anomalies Tell Us About Development and Evolution

Mark Blumberg

· Many of the most striking developmental anomalies have evolved into some of the most striking species characteristics (e.g., limbless humans, limbless snakes). (key idea: Body, brain, and behavior are shaped through development, not programmed before development)

· We take for granted how easily we can adjust to an anomalous body when we are allowed to "grow" into it. Key examples: Johnny Eck, the two-legged goat, Faith the two-legged dog (key idea: developmental flexibility)

· Some of the most devastating anomalies -- e.g., two-headedness, cyclopia -- can arise from a mutation or an environmental factor during development. Freaks are not necessarily mutants (key ideas: epigenesis; gene-environment interchangeability)

· Anomalies provide a stark contrast to "intelligent design" and a note of caution to "evolutionary design." They bring us closer to the gears and mechanisms of development, and the options available to evolution.

· Debates over whether Barack Obama is "black" recall similar discussions concerning the nature of sex. Nature often offers ambiguities, and it is the human inability to grasp ambiguity that leads us to force natural products into human categories. But anomalies won't go away so easily, because they are an integral part of nature

Freaks of Nature

What Anomalies Tell Us About Development and Evolution

Mark Blumberg

Description

In most respects, Abigail and Brittany Hensel are normal American twins. Born and raised in a small town, they enjoy a close relationship, though each has her own tastes and personality. But the Hensels also share a body. Their two heads sit side-by-side on a single torso, with two arms and two legs. They have not only survived, but have developed into athletic, graceful young women. And that, writes Mark S. Blumberg, opens an extraordinary window onto human development and evolution.

In Freaks of Nature, Blumberg turns a scientist's eye on the oddities of nature, showing how a subject once relegated to the sideshow can help explain some of the deepest complexities of biology. Why, for example, does a two-headed human so resemble a two-headed minnow?
What we need to understand, Blumberg argues, is that anomalies are the natural products of development, and it is through developmental mechanisms that evolution works. Freaks of Nature induces a kind of intellectual vertigo as it upends our intuitive understanding of biology. What really is an anomaly? Why is a limbless human a "freak," but a limbless reptile-a snake-a successful variation?

What we see as deformities, Blumberg writes, are merely alternative paths for development, which challenge both the creature itself and our ability to fit it into our familiar categories. Rather than mere dead-ends, many anomalies prove surprisingly survivable-as in the case of the goat without forelimbs that learned to walk upright. Blumberg explains how such variations occur, and points
to the success of the Hensel sisters and the goat as examples of the extraordinary flexibility inherent in individual development.

In taking seriously a subject that has often been shunned as discomfiting and embarrassing, Mark Blumberg sheds new light on how individuals-and entire species-develop, survive, and evolve.

Freaks of Nature

What Anomalies Tell Us About Development and Evolution

Mark Blumberg

Table of Contents

INTRODUCTIONChapter 1: A PARLIAMENT OF MONSTERS: On the breadth and scope of developmental anomaliesChapter 2: ARRESTING FEATURES: Development is all about timeChapter 3: DO THE LOCOMOTION: How we learn to move our bodiesChapter 4: LIFE AND LIMB: How limbs are made, lost, replaced, and transformedChapter 5: ANYTHING GOES: When it comes to sex, expect ambiguityEPILOGUE: MONSTROUS BEHAVIOR: We still have much to learn from the odd and unusualNotesSources and Suggested ReadingAcknowledgmentsIndex

Freaks of Nature

What Anomalies Tell Us About Development and Evolution

Mark Blumberg

Author Information

Mark Blumberg is Professor and Starch Faculty Fellow at the University of Iowa. The author of two books and more than eighty journal articles and chapters on a wide variety of subjects, he currently serves as Editor-in-Chief of the journal Behavioral Neuroscience and as President of the International Society for Developmental Psychobiology.